public Collection()
{
this._Collection_Contribution_Mappings = new EntitySet<Collection_Contribution_Mapping>(new Action<Collection_Contribution_Mapping>(this.attach_Collection_Contribution_Mappings), new Action<Collection_Contribution_Mapping>(this.detach_Collection_Contribution_Mappings));
this._User = default(EntityRef<User>);
this._Activity = default(EntityRef<Activity>);
OnCreated();
}